"""
求圆面积
"""
def CalCircleArea(r):
    s = 3.14 * r * r
    return s

r = eval(input("输入r的值："))
s = CalCircleArea(r) # 将函数的返回值赋值给变量s
print("半径为：%.2f的圆的面积为：%.2f"%(r,s))

def CalCircleArea1(r):
    s = 3.14*r*r
    print('半径为%d的圆的面积为：%.2f' % (r, s))

CalCircleArea1(3)
CalCircleArea1(5)



